An agricultural harvester, such as a windrower or combine, is a large machine used to harvest a variety of crops from a field. In the case of a combine, during a harvesting operation, a header at the front of the combine cuts ripened crop from the field. In the case of thinner stemmed crops such as soybeans, wheat, etc. which may be cut with a sickle bar carrying a plurality of knives, the header may also be known as a cutting platform. A feederhouse supporting the header transfers the crop material into the combine. Threshing and separating assemblies within the combine remove grain from the crop material and transfer the clean grain to a grain tank for temporary holding. Crop material other than grain exits from the rear of the combine. An unloading auger transfers the clean grain from the grain tank to a truck or grain cart for transport, or to another receiving bin for holding.
In the case of a windrower, during a harvesting operation, a header at the front of the windrower cuts ripened crop from the field. The crop is transported to the rear of the header and forming shields form a windrow of the crop between the tires of the vehicle for natural dry down of the crop. A subsequent field operation picks up the windrows for further processing, such as separating and cleaning in the case of grain crops, or baling or chopping in the case of hay.
A cutting platform may generally be of two types. One type typically has a sheet metal floor with a dual feed auger near the rear of the cutting platform for feeding the crop material longitudinally to the feeder housing. A cutting platform of this type with auger feed is more common.
Another type of cutting platform, also known as a draper platform, utilizes a flat, wide belt, referred to as a draper or draper belt to convey crop material. The arrangement and number of belts vary among platforms. One style of draper platform used on a combine has two side belts that convey crop material longitudinally, to the center of the platform, where a center feed belt moves the crop material laterally into the feeder housing. Each belt is wrapped around a pair of rollers, one being a drive roller and the other being an idler roller. An example of this type draper arrangement is disclosed in U.S. Pat. No. 6,202,397, which is assigned to the assignee of the present invention.
An advantage of a draper platform is that larger amounts of crop material can be transported without plugging, etc. For example, with wide platforms approaching 40 feet or even larger, the amount of crop material transported to the feeder housing can be substantial. With an auger feed platform, the crop material may bind between the auger and the back wall of the platform. In contrast, with a draper platform, the crop material is carried on top of the belt with less chance for plugging.
One of the primary crops for draper platforms in the windrower application is canola. Canola is a dense, intertwining crop that can be difficult to cut and converge into a windrow. The seed pods are also vulnerable to shatter with resulting grain loss, particularly if the crop is mature. The inherent difficulty in harvesting crops such as canola can result in a crop flow stoppage on the platform (plugging). Unplugging the platform is not only difficult, but typically results in a large pile of crop in the windrow and grain loss from shattering. Crop piles in the windrow are very undesirable not only because the crop will cure at a slower rate than the rest of the windrow but, more importantly, because the combine operation that follows becomes difficult. The combine operator must approach the pile very slowly and carefully feed the material into the machine to prevent slugging of the combine rotor.
Plugs on current draper platforms on windrowers are typically cleared by raising the platform and backing the machine out of the crop. If this is not effective, the reel may be raised of lowered, the platform may be raised or lowered, or the machine may be moved back and forth until the crop flow is started again. In some cases it may be necessary to remove crop from the platform manually.
With current draper designs, the platform is engaged in the forward direction by a switch in the right hand console. The switch is latched in position. The reel can be reversed by moving the same switch to a second, momentary position. Only the reel is reversed. Other components on the platform are off. Reversing the reel effectively clears the platform, particularly if the reel is moved back and/or down as necessary to engage the crop. If the machine is moved in the reverse direction at the same time, the crop is discharged with minimum windrow disruption.
This operational process is difficult to coordinate. The platform engage switch on the console must be held in the platform reverse position while moving the hydro handle rearward to reverse the machine. Both of these functions are right hand functions. In addition, a button on the hydro handle must be activated to move the reel rearward and downward and the machine must be controlled with the steering wheel as it moves rearward. A typical scenario has the operator's right hand on the console to hold the platform engage switch in the reverse position, his left hand crossing to the hydro handle to move the machine rearward and reposition the reel, and the steering wheel left uncontrolled.
What is needed in the art is an agricultural harvester with a draper cutting platform which can be more easily cleared upon occurrence of a plug.